EF4 + CTP5 + CF:DbContext继承? [英] EF4 + CTP5 + CF: DbContext inheritance?
问题描述
我有一个分层 DbContext
结构,我想要一个专门的
DbContext
及其拥有
DbSets
继承
DbSets
BaseDbContext
。
访问基础 ObjectContext
with
(( IObjectContextAdapter
)this)。 ObjectContext
需要很长时间(几分钟)到
recei是ObjectContext。
是否存在问题 DbContext
在CT5中获得
ObjectContext
from derived
DbContext
是不是很有效?
结构是: DbContext(EF4)< - myBaseDbContext< - mySpecializedDbContext
期待任何答案 ... chears& thx。
我认为CTP5中的DbContext没有问题,我认为你可以寻找另一个原因。此外,你可以阅读有关如何在CTP5中创建Context对象的信息:
创建一个上下文
开始使用类进行数据访问的最简单方法是定义一个派生自System.Data.Entity.DbContext的上下文并公开一个类型我模型中每个类的DbSet< TEntity>。
我们现在开始使用CTP5中的类型,因此我们需要添加对CTP5程序集的引用:
- 项目 - >添加参考…
- 选择".NET”标签
- 从列表中选择“ EntityFramework”
- 点击"确定&rdqu" o;
您还需要对现有实体框架程序集的引用:
- 项目 - >添加参考…
- 选择".NET”标签
- 选择“ System.Data.Entity”从列表中
- 点击"确定"”
在Program.cs的顶部为System.Data.Entity添加using语句
使用 System.Data.Entity;
在我们定义的现有类下面添加派生上下文
公共类 ProductContext : DbContext
{
public DbSet < 类别>类别{ get ; set ; }
public DbSet < 产品跨度>>产品{获取; set ; }
}
更多信息,请阅读
演练。
感谢
Hi, i have a hierarchical DbContext
structure, where i would like a specialized
DbContext
with its own
DbSets
to inherit the
DbSets
of a
BaseDbContext
.
While accessing the underlying ObjectContext
with
((IObjectContextAdapter
)this).ObjectContext
it takes to long time (several minutes) to
receive the ObjectContext.
Is there an issue with DbContext
in CT5, that getting an
ObjectContext
from derived
DbContext
is not performantly possible?
The structure is: DbContext(EF4) <- myBaseDbContext <- mySpecializedDbContext
Looking forward to any answer...chears & thx.
Hi,
I don't think there's an issue with DbContext in CTP5, I think you could look for another reason. Further, you can read this about how to create Context Object in CTP5:
Create a Context
The simplest way to start using the classes for data access is to define a context that derives from System.Data.Entity.DbContext and exposes a typed DbSet<TEntity> for each class in my model.
We’re now starting to use types from CTP5 so we need to add a reference to the CTP5 assembly:
- Project -> Add Reference…
- Select the “.NET” tab
- Select “EntityFramework” from the list
- Click “OK”
You’ll also need a reference to the existing Entity Framework assembly:
- Project -> Add Reference…
- Select the “.NET” tab
- Select “System.Data.Entity” from the list
- Click “OK”
Add a using statement for System.Data.Entity at the top of Program.cs
using System.Data.Entity;
Add a derived context below the existing classes that we’ve defined
public class ProductContext : DbContext { public DbSet<Category> Categories { get; set; } public DbSet<Product> Products { get; set; } }More infomation, read the walkthrough.
thanks
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